Variable-speed gearing.



E. W. THOMAS.

VARIABLE swan GEARING.

ATPLIGA'IION FILED OUT. 3L 1614 Patented Jan. 12, 1915.

.3 SHEETS-SHEET 1. By. 3.

W. THOMAS.

VARIABLE SPEED GEARING.

APPLIHATION IILED 001. 31. m4

Patented J an. 12, 1915.

3 SHEETSSHEE I 2.

E. W. THOMAS.

VARIABLE $PEED GEARING \PPLIUATION FILED 00131. mu.

Patented Jan. 12, 1915 3 SHEETS SHEII'E' i EDWARD WILLIAM THOMAS, OF LUTON, ENGLAND.

VARIABLE-SPEED GEABIN G.

Specification of Letters Patent.

Patented Jan. 1 2, 1915.

Application filed October 31. 1914. Serial No. 869,718.

To all whom it may concern Be it known that I, Eowano VVILLIAM THOMAS, afi ubjeet of the King of Great Britain and Ireland, residing at 57 Leagrave road, Luton, in the county of Bedl'ord, England. have invented new and useful Improvements Relating to Variable- Speed (iearing. of which the following is a specification.

This invention relates to variable speed gearing and is intended more especially for the gear boxes of motor cars. It eml'iraces change-speed mechanism of that type in whirh there is, no load at first upon any gear wheel which slides into toothed engagement with another, hut the load comes upon it only a lter the teeth are in mesh through the engagement of the dogs. (I use this word throughout for convenience. without desiring to limit the invention to a dog or any other kind of clutch.)

(lertain ad\antages,such as reduction in length of box and simplicity of operation. will be manilwt from the following deserip' tion of the invention.

I will describe my invention as carried out in a box having as usual the engine and main shafts inserted into the box end. to end parallel to a lay shalt. It will be understood nevertheless that the box might he of the hind where there is no lay shaft but in which the ngine and main shafts overlap.

it is fairly customary for the first-speedand-rmerse wheel to he splined' on the lay shal't (or on the main shaft where the lay shalt is ;lli;-.('llt). but it is essential to the woi-hing of my invention that this wheel should be loose on its shaft. In actual practice. how ver. l utilize this wheel only as a lirst specd or a first-am'-serond-speed driv ing wheel and I make it have sullirient drag to be given an initial movement when the car is starting from rest, which will prevent any undue delay in its sliding into gear with the drivel. wheel splined on to the main shaft whi h would then be stationary.

l will deseribe the said invention further. with reference to the accompanying drawings in which:

Figure 5 in a soetional plan ill a 3-speed gear. Fig. i is a sectional plan of a reverse gear Hlllttllllt for use therewith. Fig :1 is an end view oi Fig. 2. Fig. 4 is a sectional plan 01' a -l-speed gea r. Fig. 5 is a sectional plan of a reverse gear suitahle for use therewith, introducii'ig also a slightmodification of the locking mechanism seen at right angles to Fig. 7.

Describing my invention as applied to a 3-speed gear box of the kindaal'iove referred to. illustrated in Fig. l, the lay shaft T carries the two constant-mesh wheels B and E keyed thereon as at A} the first one B, (sometimes called the operating wheel.) at the forward end and the second wheel E at the rear. Wheel I5 is in eontant mesh with the stem pinion A, formed integrally with the. engine shaft. 'heel E is contantly engaged with the gear wheel l. which is freely mounted upon the. main shaft H. The wheel C lying between wheels B and E (an he slid toward wheel [3 and become rlutched thereto. Wheel may he moved in mesh with wheel l) whhh is splined on to the main shaft ll hetween wheels F and A and is adapted to slide toward either of these lattenand beconu: clutched to them. in no case is there any load upon the teeth of gear wheels while they are sliding into mesh. In this 3-speed box the top speed is obtained by sliding wheel I) into engagement with wheel A, the wheels C and D being con'ipletely out of mesh with any other wheel. and therefore wasting no energy. For the second speed, the wheel I) is slid back till it clutches with wheel F. For this purpose wheel D is provided with a long hoss for carrying the dogs in closer proximity to those upon the wheel l may here. mention the most important ieature of my invention, a feature which u I eeononuzes room in the box. and this is that the wheel (l is given an identical and synchronous travel with wheel I), in order to prevent their meshing with one another. if wheel were left stationary, the intermeshing could he avoided only by leaving a. greater distance between them in the design of the box, which would therefore be longer by this amount. 1 thus attain a valuable result by sliding wheels (I and D s multaneously by means of the same shifting mechanism. and this being so. i find it unnecessary to provide a separate locking device for wheel (I when sliding simultaneously with wheel D. l

For the first or low speed, wheel C is slid into gear with wheel D, and only after. the wheels have meshed through, say, half of their width (or more or less), the dogs on wheel C engage with those upon wheel B, and wheel thereupon becomes fast upon the la shaft, T. For the reverse, as will be seen in either Fig. 2 or Fig. 3, the ordinary sliding action may be resorted to, and .a double pinion G is mounted on a third shaft U and slid into engagement with wheels D and E simultaneously. I

The drag of the wheel (J (Fig. 1 produced by closing its oil spiral w .011

is known to cause considerable pressure in the oil between the lav shaft and the wheel,

4-speed and reverse box, illustrated iii-Fig.

4., the same general principle is observe The essential. modifications are that the slidable wheels on the lay and main shafts, namely, the wheelsC and D, shall have two points of engagement with one another, representing dlfl'erent speed ratios, and for bringing these into mesh in the proper order, it is convenient that one shall be, as it g were, within the length of the other, so that -wise in the form of a it will gear both when slid forward and backward. Thus, wheel C is made conveniently shorter than wheel D in order that it may be as li ht as possible, being subject to sudden speerf variation. The wheel C moreover isadapted to clutch against wheel E when slid up to it. In this rticular construction and arrangement 0 gear box, for four speeds and reverse, the wheel C isv practically a loose sleeve with a gear wheel C on the forward endand a smaller gear wheel C on the rear. The wheel D is likesleeve but splined on the main shaft H, having a forward gear wheel D (adapted to engage wheel C) and a rear gear wheel D (adapted to engage with wheel C). In neutral position, the wheels C C lie between wheels-D D and just clear of the same, the amount of the clearance being as small as is practicable.

For top-speed direct drive, wheel D is slid until wheel D clutches pinion A into the engine shaft, and interference of wheel D '"wheel E, the en a is prevented, not by leaving from wheel F on the one hand and pinion A.

on the other. Wheel C is slid along simultaneously with wheel D and then carried along still farther until wheel C meshes with wheel I) and finally clutches with wheel B. The drive will then be from pinion A through wheels B C to D When first or low speed is required wheel ,0 is slid backward, thus releasing the drive between wheels C and D" Almost at my wheel C engageswheel D, coming clutched against wheel E, where upon the power is carried through wheels A, B, E, C D The reverse as clearly shown in Fig. 5 is obtained by slidin the duplex pinion untilits gear whee Gr meshes with wheel D and the wheel G with ement of wheel G with wheel E bein s ig tly in advance of wheel G with whe'elD, in. order to insure prompt engagement of the other teeth when the, car is at rest.

The duplex sleeve ,0 of Fig. 4 may be divided into a pair of wheels C and C as shown in Fi 5, each one capable of driving independently its particular gear wheel 1) or wheel D when its dogs are clutched. Even in its divided form however, the sleeve C is slid along the shaft as if it were one unit by means of a fork Y (see also Fig. 6) which is channeled so as to tie-the two wheels 0 C loosely together when passed over their flanges which butt against one another.

Referring now to Figs. 7 and 8, certain operating levers Kand L are keyed to the usual sliding tube M carried on the rod Z and actuated direct from the change speed lever at the side of the chauffeur. Upon the tube M is loosely mounted a sleeve N carrying an arm J fixed thereon, the purpose of which is to' communicate a parallel sliding movement to a locking bar 0 carried in guides X X. This bar is provided with a groove Q alon its upper side adapted to restrain the shi ting rodsPRS, owing to the latter having heels V projecting into said groove Q, which, however, has gaps W at intervals. The position in Fig. 7 is as set for the reverse, and it will benoticed that a gap 1n the bar 0 comes ,ex'actly opposite the shifting rod P, pelrmitting that rod to be moved longitudinally by the swing of the lever K, so causing'the reverse gears G and (i to come into operation. It will be noticed also that in this position the shiftin rods R and S, operating the 1st speed and 2nd and 3rd, remain locked by the bar 0, due to the absence of any gap W opposite such rods.

The arm J partakes of the sliding movement of the levers K and L only and not of their swinging or angular movement.

The 1st speed is obtained by moving bodily the levers L, J and wheel K, by means of the sliding tube M until K engages with the shifting rod R; the shifting rods P and 5 being free of the levers L and K. The arm J will then have moved the locking bar (l, so as to bring a gap in the letter opposite the shifting le or R, but will have looked the shifting rods 1 and This enables the 1st speed wheel C to he slid into engagement.

Av further movement of the levers L, K, and J, will bring the lever L into engage nient with the shifting rod S. but the lever K, owing to the length of its shitting boss, will still be in engagement with shifting rod it, thereby enabling the wheels C and D to be operated simultaneously. When in this position the shifting rod 1 remains locked by there being no opposing gap in the locking bar 0.

Fig. 8 shows tlearly tllt' form of the shifting rod 5, (1 and ll being similar also) the locking bar 0, and the method of mounting the shifting levers J and l 1. In variable speed gearing, a main shaft, a spur wheel on one end of the main shaft, a driven wheel on the opposite end of the main shaft, and an intermediate sliding gear splined to the main shaft, a lay shaft associated With the main shaft, a drive \\'llt\l keyed on, one end of the lay shaft and in mesh with the spur wheel of the main shaft, a wheel keyed on the opposite end of the ay shaft and in mesh with the second mentioned wheel, a sliding wheel on the lay shaft. adapted to mesh with the sliding wheel of the rim] vshalt, said sliding wheel of the lay shaft arlaptrd to be clutched with the drive whet-l, and tlusliding wheel of the main shaft adapted to he elutrhed to the tlrimn wheel of the main shalt, and means for ell'rcting said clutching operations, and adapted to slide the gear. imultaneousl, in the sam direction.

2. In variable speed gearing, a main shaft, spaced gear wheels on the main shaft I and an intermediate slidable gear splined to the main shaft. a lay shaft, soaced gears keyed on the lay shaft and an intern'iediate slid-able gear, said last mentioned slidable gear adapted to he clutched with one of the gems of the lay shall, said slidable gears adapted to mesh w ith t-aeh other, means for sliding the slidahle gears, comprising rods, a sliding tube, and arms carried thereby,

,means for locking the rods, said looking means emnprising a sleere loosely carried on the sliding tube, an arm on the sleeve and a slidahle har engaged with one end of the arm, said bar having a longitudinal groove, a portion of each of the sliding rods extending into the groove, and the wall of the groove having recesses for allowing the sliding rods to move therefrom.

3. ln \ariable speed gearing, a main shaft, a gear wheel mounted on each end. of the main shaft, an intermediate sliding wheel spliin'd on the main shaft, and having gear wheels of different diameters, a lay shaft associated with the main shaft, a gear wheel keyed on each end of the lay shaft, and an intermediate sliding wheel having gear whet-ls of different diameters, the gear wheels on the ends of the main shaft adapted to mesh with the respective gear wheels on the ends of the shaft,.the sliding gear wheels of the lay shaft adapted to mesh alternatively with the peripheries of the sliding intermediate gear wheels of the main shaft, all of said wheels have clutch fares, and means for sliding said slidable glilll'hl.

4. ln combination, a shaft, a gear wheel. on the shaft, said gear wheel having a spiral oil groove closed at one end, whereby rotation of the gear wheel causes a pressure of the oil held in the groove.

In witness whereof I ha ve hereunto atlixed my signature in the presence of the two subsi'rihing witnesses.

El) WARD WlLLIAM THOMAS Witnesses:

L. nni. Monr, Gnonon 11AM. 

